use std::env;
use std::fs;
use std::path::PathBuf;

fn main() {
    // CARGO_MANIFEST_DIR -> 项目根目录路径
    // CARGO_TARGET_DIR -> 用户自定义了 target 目录，使用该变量
    let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
    let target_dir = env::var("CARGO_TARGET_DIR")
        .ok()
        .map(PathBuf::from)
        .unwrap_or_else(|| PathBuf::from(&manifest_dir).join("target"));

    // PROFILE -> 获取当前构建配置文件（debug/release）
    let profile = env::var("PROFILE").unwrap();
    // let output_dir = target_dir.join(&profile);

    // 在 target/debug/ 或 target/release/ 下创建 bin2 目录
    let output_dir = target_dir.join(&profile).join("bin2");

    // cargo:rerun-if-changed -> 当指定文件变化时，重新运行 xxx
    println!("cargo:rerun-if-changed=build.rs");
    println!("cargo:rerun-if-changed=rshim.lua");
    println!("cargo:rustc-env=OUTPUT_DIR={}", output_dir.display());

    // 创建目录
    let subdirs = ["bin", "tools"];
    for subdir in &subdirs {
        let path = output_dir.join(subdir);
        if !path.exists() {
            fs::create_dir_all(&path).expect(&format!("Failed to create {} directory", subdir));
            println!("Created: {:?}", path);
        }
    }

    // 复制文件
    let source = PathBuf::from(&manifest_dir).join("mimic.lua");
    let destination = output_dir.join("rshim.lua");

    if source.exists() {
        fs::copy(&source, &destination).expect("Failed to copy mimic.lua");
        println!("Copied mimic.lua to: {:?}", destination);
    } else {
        panic!("mimic.lua not found at: {:?}", source);
    }
}